The xanthic undulated triggerfish is a mystery among aberrant reef fish, but thankfully we don’t usually have to wait too long in between freshly caught specimens. At a rate of roughly one xanthic Balistapus undulatus every twelve months or se, we get to see this oddity of the reef fish world with ever increasingly better documentation.

As with the last few xanthic triggers, the latest one to be collected and photographed comes to us from the Philippines via RVS Fishworld. We know it seems like we’ve written about this xanthic triggerfish phenomenon enough times in the past, but to us this fish is still very special.

Ever since ‘Melekeok’s Golden Triggerfish’ first appeared on the cover of Freshwater and Marine Aquarium Magazine (FAMA) ever so long ago, the xanthic triggerfish has held a mythical place in our rare fish psyche. Interestingly, since we’ve been able to study a handful of xanthic triggerfish over the years, we’ve noticed that there is a pattern in their off-coloration.

To date, all xanthic undulated triggerfish have shown a unique pattern of spots replacing their usual undulating lines. Where the network of lines is preserved, the typical green and orange-lined coloration remains, but where the lines break up into the few fine spots, the xanthic golden coloration takes over.

The freshest specimen of golden xanthic undulated triggerfish follows this tendency as well, with a golden yellow coloration covering most of the body. This chromatic deviation is particularly apparent on the tail spines of this triggerfish, with each spine being a bright orange instead of the usual black in normally colored specimens.

It’s a pity that undulated triggerfish are so mean, get so large, and are just about the worst fish you could possibly put into a community reef aquarium. If this fish was reef safe the golden undulated triggerfish would be as revered as a peppermint angelfish, but alas, xanthic or not, the undulated triggerfish belongs in a maximum security aquarium for monster tank busters.